Synthesis of Brominated Alkanes via Heterogeneous Catalytic Distillation over Al2O3/SO42−/ZrO2

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1464
Author(s):  
Su Yang ◽  
Xiaoxuan Guo ◽  
Xiaomei Pan ◽  
Liuyu Gu ◽  
Xueping Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Reactive Distillation ◽  
Practical Method ◽  
Acid Sites ◽  
Side Reactions ◽  
Catalytic Distillation ◽  
Characterization Methods ◽  
X Ray ◽  
Heterogeneous Catalytic ◽  
Microscopic Morphology

Concentrated sulfuric acid is generally used as a catalyst for producing brominated alkanes in traditional methods, but is highly corrosive and difficult to separate. This work reports the preparation of bromopropane from n-propanol based on a reactive distillation strategy combined with alumina-modified sulfated zirconia (Al2O3/SO42−/ZrO2) as a heterogenous catalyst. As expected, under the optimum reaction conditions (110 °C), the yield of bromopropane was 96.18% without side reactions due to the reactive distillation strategy. Meanwhile, the microscopic morphology and performance of Al2O3/SO42−/ZrO2 were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunner–Emmet–Teller (BET), Fourier transform infrared spectroscopy (FT–IR), and other characterization methods. The results confirmed that the morphology of zirconia sulfate is effectively regulated by the modification method of alumina, and more edges and angles provide more catalytic acid sites for the reaction. Furthermore, Al2O3/SO42−/ZrO2 exhibited high stability and remarkable reusability due to the strong chemical bond Zr–Al–Zr. This work provides a practical method for the preparation of bromopropane and can be further extended to the preparation of other bromoalkanes.

scholarly journals Influence of Sulfur-Containing Sodium Salt Poisoned V2O5–WO3/TiO2 Catalysts on SO2–SO3 Conversion and NO Removal

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 541 ◽  
Author(s):  
Haiping Xiao ◽  
Chaozong Dou ◽  
Hao Shi ◽  
Jinlin Ge ◽  
Li Cai
Keyword(s):  
Photoelectron Spectroscopy ◽  
No Reduction ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Impregnation Method ◽  
So2 Oxidation ◽  
Sodium Salts ◽  
X Ray ◽  
Temperature Programmed ◽  
Physical Features

A series of poisoned catalysts with various forms and contents of sodium salts (Na2SO4 and Na2S2O7) were prepared using the wet impregnation method. The influence of sodium salts poisoned catalysts on SO2 oxidation and NO reduction was investigated. The chemical and physical features of the catalysts were characterized via NH3-temperature programmed desorption (NH3-TPD), H2-temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FT-IR). The results showed that sodium salts poisoned catalysts led to a decrease in the denitration efficiency. The 3.6% Na2SO4 poisoned catalyst was the most severely deactivated with denitration efficiency of only 50.97% at 350 °C. The introduction of SO42− and S2O72− created new Brønsted acid sites, which facilitated the adsorption of NH3 and NO reduction. The sodium salts poisoned catalysts significantly increased the conversion of SO2–SO3. 3.6%Na2S2O7 poisoned catalyst had the strongest effect on SO2 oxidation and the catalyst achieved a maximum SO2–SO3-conversion of 1.44% at 410 °C. Characterization results showed sodium salts poisoned catalysts consumed the active ingredient and lowered the V4+/V5+ ratio, which suppressed catalytic performance. However, they increased the content of chemically adsorbed oxygen and the strength of V5+=O bonds, which promoted SO2 oxidation.

scholarly journals Oxidative Desulfurization of Tire Pyrolysis Oil over Molybdenum Heteropolyacid Loaded Mesoporous Catalysts

Reactions ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 457-472
Author(s):  
Jasmine Kaur ◽  
Sundaramurthy Vedachalam ◽  
Philip Boahene ◽  
Ajay K. Dalai
Keyword(s):  
Sulfur Content ◽  
Photoelectron Spectroscopy ◽  
Supported Catalysts ◽  
Surface Acidity ◽  
Oxidative Desulfurization ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Process Conditions ◽  
Pyrolysis Oil ◽  
X Ray

Pyrolysis oil derived from waste tires consists of sulfur content in the range of 7000 to 9000 ppm. For use in diesel engines, its sulfur content must be lowered to 10 to 15 ppm. Though conventional hydrodesulfurization is suitable for the removal of sulfur from tire pyrolysis oil, its high cost provides an avenue for alternative desulfurization technologies to be explored. In this study, oxidative desulfurization (ODS), a low-cost technology, was explored for the desulfurization of tire pyrolysis oil. Two categories of titanium-incorporated mesoporous supports with 20 wt% loaded heteropoly molybdic acid catalyst (HPMo/Ti-Al2O3 and HPMo/Ti-TUD-1) were developed and tested for ODS of tire pyrolysis oil at mild process conditions. Catalysts were characterized by X-ray diffraction, BET-N2 physisorption, and X-ray photoelectron spectroscopy (XPS). The incorporation of Ti into Al2O3 and TUD-1 frameworks was confirmed by XPS. The surface acidity of catalysts was studied by the temperature-programmed desorption of NH3 and pyridine FTIR analyses. HPMo/Ti-Al2O3 and HPMo/Ti-TUD-1 catalysts contained both Lewis and Brønsted acid sites. The presence of titanium in catalysts was found to promote the ODS activity of phosphomolybdic acid. The Ti-TUD-1-supported catalysts performed better than the Ti-Al2O3-supported catalysts for the ODS of tire pyrolysis oil. Hydrogen peroxide and cumene peroxide were found to be better oxidants than tert-butyl hydroperoxide for oxidizing sulfur compounds of tire pyrolysis oil. Process parameter optimization by the design of experiments was conducted with an optimal catalyst along with the catalyst regeneration study. An ANOVA statistical analysis demonstrated that the oxidant/sulfur and catalyst/oil ratios were more significant than the reaction temperature for the ODS of tire pyrolysis oil. It followed the pseudo-first-order kinetics over HPMo/Ti-TUD-1.

scholarly journals Mechanism and Performance of the SCR of NO with NH3 over Sulfated Sintered Ore Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 90 ◽  
Author(s):  
Wangsheng Chen ◽  
Fali Hu ◽  
Linbo Qin ◽  
Jun Han ◽  
Bo Zhao ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Space Velocity ◽  
Acid Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
And Performance ◽  
Diffuse Reflectance Infrared

A sulfated sintered ore catalyst (SSOC) was prepared to improve the denitration performance of the sintered ore catalyst (SOC). The catalysts were characterized by X-ray Fluorescence Spectrometry (XRF), Brunauer–Emmett–Teller (BET) analyzer, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared spectroscopy (DRIFTS) to understand the NH3-selective catalytic reduction (SCR) reaction mechanism. Moreover, the denitration performance and stability of SSOC were also investigated. The experimental results indicated that there were more Brønsted acid sites at the surface of SSOC after the treatment by sulfuric acid, which lead to the enhancement of the adsorption capacity of NH3 and NO. Meanwhile, Lewis acid sites were also observed at the SSOC surface. The reaction between −NH2, NH 4 + and NO (E-R mechanism) and the reaction of the coordinated ammonia with the adsorbed NO2 (L-H mechanism) were attributed to NOx reduction. The maximum denitration efficiency over the SSOC, which was about 92%, occurred at 300 °C, with a 1.0 NH3/NO ratio, and 5000 h−1 gas hourly space velocity (GHSV).

scholarly journals Hydroprocessing of Oleic Acid for Production of Jet-Fuel Range Hydrocarbons over Cu and FeCu Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1051
Author(s):  
Afees A. Ayandiran ◽  
Philip E. Boahene ◽  
Ajay K. Dalai ◽  
Yongfeng Hu
Keyword(s):  
Oleic Acid ◽  
Photoelectron Spectroscopy ◽  
Textural Properties ◽  
Acid Sites ◽  
Jet Fuel ◽  
Metal Dispersion ◽  
X Ray ◽  
Metal Support Interaction ◽  
High Metal ◽  
Al2o3 Catalyst

In the present study, a series of monometallic Cu/SiO2-Al2O3 catalysts exhibited immense potential in the hydroprocessing of oleic acid to produce jet-fuel range hydrocarbons. The synergistic effect of Fe on the monometallic Cu/SiO2-Al2O3 catalysts of variable Cu loadings (5–15 wt%) was ascertained by varying Fe contents in the range of 1–5 wt% on the optimized 13% Cu/SiO2-Al2O3 catalyst. At 340 °C and 2.07 MPa H2 pressure, the jet-fuel range hydrocarbons yield and selectivities of 51.8% and 53.8%, respectively, were recorded for the Fe(3)-Cu(13)/SiO2-Al2O3 catalyst. To investigate the influence of acidity of support on the cracking of oleic acid, ZSM-5 (Zeolite Socony Mobil–5) and HZSM-5(Protonated Zeolite Socony Mobil–5)-supported 3% Fe-13% Cu were also evaluated at 300–340 °C and 2.07 MPa H2 pressure. Extensive techniques including N2 sorption analysis, pyridine- Fourier Transform Infrared Spectroscopy (Pyridine-FTIR), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and H2-Temperature Programmed Reduction (H2-TPR) analyses were used to characterize the materials. XPS analysis revealed the existence of Cu1+ phase in the Fe(3)-Cu(13)/SiO2-Al2O3 catalyst, while Cu metal was predominant in both the ZSM-5 and HZSM-5-supported FeCu catalysts. The lowest crystallite size of Fe(3)-Cu(13)/SiO2-Al2O3 was confirmed by XRD, indicating high metal dispersion and corroborated by the weakest metal–support interaction revealed from the TPR profile of this catalyst. CO chemisorption also confirmed high metal dispersion (8.4%) for the Fe(3)-Cu(13)/SiO2-Al2O3 catalyst. The lowest and mildest Brønsted/Lewis acid sites ratio was recorded from the pyridine–FTIR analysis for this catalyst. The highest jet-fuel range hydrocarbons yield of 59.5% and 73.6% selectivity were recorded for the Fe(3)-Cu(13)/SiO2-Al2O3 catalyst evaluated at 300 °C and 2.07 MPa H2 pressure, which can be attributed to its desirable textural properties, high oxophilic iron content, high metal dispersion and mild Brønsted acid sites present in this catalyst.

scholarly journals Synthesis and Characterization of a New Aluminum-Doped Bismuth Subcarbonate

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 466
Author(s):  
Loisangela Álvarez ◽  
Blanca Rojas de Gascue ◽  
Rolando J. Tremont ◽  
Edgar Márquez ◽  
Euclides J. Velazco
Keyword(s):  
Infrared Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Characterization Methods ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Anionic Part

A new compound, Bi2O2CO3:Al, was synthesized by the coprecipitation method. The characterization was done by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), electronic scanning microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The characterization methods allowed to identify the Bi2O2CO3:Al compound, such as the Al-doped Bi2O2CO3 by XRD, the anionic part (CO32−) by FTIR, and the presence of aluminum in the compound by XPS and EDX. It was confirmed to have a nanostructure like a nanosheet and a microstructure that resembles a type sponge by SEM.

scholarly journals Silver–palladium catalysts for the direct synthesis of hydrogen peroxide

2017 ◽  
Vol 376 (2110) ◽  
pp. 20170058 ◽  
Author(s):  
Zainab Khan ◽  
Nicholas F. Dummer ◽  
Jennifer K. Edwards
Keyword(s):  
Hydrogen Peroxide ◽  
Photoelectron Spectroscopy ◽  
Palladium Catalysts ◽  
Bimetallic Catalyst ◽  
Direct Synthesis ◽  
Side Reactions ◽  
X Ray ◽  
Temperature Programmed ◽  
Silver Palladium ◽  
Subsequent Decomposition

A series of bimetallic silver–palladium catalysts supported on titania were prepared by wet impregnation and assessed for the direct synthesis of hydrogen peroxide, and its subsequent side reactions. The addition of silver to a palladium catalyst was found to significantly decrease hydrogen peroxide productivity and hydrogenation, but crucially increase the rate of decomposition. The decomposition product, which is predominantly hydroxyl radicals, can be used to decrease bacterial colonies. The interaction between silver and palladium was characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The results of the TPR and XPS indicated the formation of a silver–palladium alloy. The optimal 1% Ag–4% Pd/TiO 2 bimetallic catalyst was able to produce approximately 200 ppm of H 2 O 2 in 30 min. The findings demonstrate that AgPd/TiO 2 catalysts are active for the synthesis of hydrogen peroxide and its subsequent decomposition to reactive oxygen species. The catalysts are promising for use in wastewater treatment as they combine the disinfectant properties of silver, hydrogen peroxide production and subsequent decomposition. This article is part of a discussion meeting issue ‘Providing sustainable catalytic solutions for a rapidly changing world’.

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